Two-piece plug for rotational casting process for forming suction cup integral with the molded article

ABSTRACT

A method of casting an article such as a toy in which a suction cup is integrally formed with the cast article. Also disclosed is a novel mold closure for use in a rotational casting operation to form the integral suction cup on the article.

limited States Patent [1 1 [111 3,759,480 Stier et al. Sept. 18, I973 TWO-PIECE PLUG FOR ROTATIONAL I I 425/DIG. 58, DIG. 44

CASTING PROCESS FOR FORMING v SUCTION CUP INTEGRAL WITH THE [56] References Cited MOLDED ARTICLE UNITED STATES PATENTS [75] Inventors: Barrie J. Stier, Brooklyn; Peter J. 2,874,412 2/1959 Flemming et al. 264/318 Ferrara, Rego Park; Ivan Klobas, l,775,537 9/1930 Salisbury 249/204 I New York, all of NY.

. r Primary Examiner-Robert F. White {73] Asslgnee' ztg gz g a c nt g Assistant Examiner-T. E. Balhoff g Att0mey--Sandoe, Hopgood and Calimafde [22] Filed: Apr. 26, I971 [21] Appl. No.: 137,449 I ABSTRACT A method of casting an article such as a toy in which [52] U S C] 249/142 249/55 249/121 a suction cup is integrally formed with the cast article.

264/310 Also dlsclosed 1s a novel mold closure for use in a rota- [51] Int Cl 329C 1/ tional casting operation to form the integral suction [58] Field of Search".. 249/147, 148, 175, the uncle 249/177, 204, 205; 65/226, 262; 46/32, 115; 2 Claims, 6 Drawing Figures PAIENTEDSEPWW 3.759.480

' SHEET 1 0F 2 INVENTORS 54 RI ST/ER PE 62 J FERRAIQA BY IVAN fflOBAS "PAIENTEDSEPIBW 3.759.480

SHEEI 2 OF 2 INVENTORS BARR/E 57752 PETER .Z F'R'PdRA BY .rm/v #10545 The invention relates generally to molding, and more particularly 'to a novel method and apparatus for forming a suction cup integral with the molded article.

The provision of a suction cup on an article to removably, although securely, attach an article to a surface is well known. The user of the article simply places the end of the article carrying the suction cup on a suitable surface, and then urges the article against the surface to cause the air enclosed by the suction cup to be ex pelled therefrom. The resulting reduced air pressure within the cup is sufficient to permit the external atmo- Spheric pressure present at the external surface of the suction cup to securely affix the article to the surface, so long as the reduced pressure condition continues to exist within the suction cup.

The use of casting operations to produce articles is likewise well known. For example, the production of plastic articles by casting processes has long been extensively practiced by various techniques such as extrusion molding and rotational casting operations. The use of plastic molding and casting operations are particularly wide-spread in the production of low-cost and mass-produced articles such as toys, dolls and the like.

The pleasure that may be derived from the use of toys and dolls, particularly by children, may be considerably enhanced by providing the child with the ability to affix the toy to a wall or bath surface or the like by the use of a suction cup.

There has been heretofore no practical and economical manner to provide dolls or toys formed by molding or casting operations with a suction cup. To provide the doll with a separate suction cup would require an additional manufacturing step, to wit, the attachment of the suction cup to the doll, which step would increase the manufacturing cost of the doll or toy. Since these items are, as noted above, generally low-cost items, such cost increases are unacceptable and prohibitive. Moreover, the suction cup separately attached to the doll may readily become separated therefrom during use such that the utility of the suction cup on the doll is completely destroyed.

It is thus apparent that forming a suction cup integral with the doll or toy would be the better approach However, the molding and casting art has so far failed to develop a suitable method and/or apparatus for forming an article such as a doll or toy that has a suction cup formed integrally therewith.

It is thus an object of the invention to provide an improved method for integrally forming a suction cup onto a cast or molded article.

It is another object of the invention .to provide a novel plug or mold closure for use in a rotational casting process for fabricating an article such as a doll or toy in which a suction cup is integrally formed with the finished article.

- It is a further object of the'invention to provide a method and apparatus of the type described in which the suction cup may be formed at any selected location I on the formed article.

ing. .In this process a plurality of hollow-sectional molds shaped in theform of the article to be fabricated are carried on a carrier or spider. The molds are loaded with a charge of plastisol such as a vinyl resin compounded with a plasticizer. The molds are than sealed by a plug or closure under pressure, and the molds are then rotated to evenly distribute the plastisol over the inner surface of each mold.

The plastisol within the mold is subjected to heating to gel and fuse the material. The rotation of the mold is then stopped and the mold is cooled. The closure or plug is then removed from the mold and the skin layer of the plastisol, now having a shape conforming to the shape of the interior wall of the mold, is removed from the mold, after-which suitable dyeing steps may be performed on the article to place it in its final form.

in accordance with the present invention, the conventional plug on the mold is replaced by a unique, cooperating plug such that the molded article formed by the casting operation has a suction cup integrally formed at any desired location thereon.

To the accomplishment of the above and to such further objects as may hereinafter appear, the present invention relates to a novel plug for use in a molding or casting operation, substantially as defined in the appended claims and as described in the following specification taken together with the accompanying drawing in which:

FIG. l is an elevation of a doll having a suction cup integrally formed therewith of the type that may be fabricated in accordance with the invention;

FIG. 2 is an exploded perspective view of the elements of the suction cup forming plug or mold closure of the invention;

FIG. 3 is a vertical cross-sectional view of the twopiece suction cup forming plug of the invention as assembled and inserted into a mold opening;

FIG. d is a perspective view similar to FIG. ll of a doll having an integrally formed suction cup at an alternate location;

FIG. 5 is a perspective view of a mold and closure therefor for fabricating the doll of FIG. 4i; and

FIG. ti is a cross-sectional view taken across the lines 6-6 of FIG. 5.

The mold plug or closure and article forming process of the invention provide the unique capability of fabricatingan article such as a doll, toy or the like, to which a suction cup is integrally formed. Thus, as shown in FIG. 1, a doll 10 here shown as a well-dressed and straw hat-carrying rat, has a suction cup 12 integrally formed with its base, that is, with the bottom of the dolls feet or shoes. The provision of suction cup 12 permits the child to secure doll 10 by suction to any suitable, preferably smooth, surface, so as to significantly increase the enjoyment and amusement that the child may derive from the use of the doll. It will be understood that the suction cup may be formed at any desired location on the doll, to thereby increase the variety of doll mounting that can be achieved by the use of the suction cup. 3

Doll 10 of F iG. 11 is fabricated by the molding apparatus illustrated in FIGS. 2 and 3. That apparatus comprises a mold generally designated 14 which includes a mold body 16 of a suitable material such as copper. Body 16 is of a desired shape and size conforming to the shape and size of doll 10 which is to be molded therein. Mold body 16 includes a mold opening 18 defined by a tapered annulus or ring 20 formed integral with the mold body. The liquid plastisol is inserted into the mold body through opening 18 prior to the casting operation, after which the novel mold closure or plug of the invention is inserted into opening it? in order to seal the mold body 16 during the casting operation.

As shown in FIGS. 2 and 3, the mold closure or plug of the invention, generally designated 22, consists of a ring-shaped piece 24 having a central opening 26 formed therethrough, and an insert or mating piece 28. Piece 28 includes a cylindrical post 30 having an axial threaded bore 32 formed at one of its ends. The end of post 30 carries a disc-shaped flange 34 which in turn has a spherical portion or dome 36 centrally and preferably integrally formed thereon.

As can be seen best in FIG. 3, piece 24 is in the form of a tapered annulus, that is, the diameter of piece 24 increases linearly in the axial direction between its two major surfaces. Similarly, opening 26 formed in piece 24 is similarly tapered, that is, its diameter also increases linearly between its axial ends. Plug 22 is formed by bringing piece 28 into engagement with piece 24 such that dome 36 is inserted into the larger diameter, axial end of opening 26 in piece 24. The two plug pieces are thereafter secured by means of screws 38 beveled at their lower ends, which pass through registering, threaded holes formed in flange 34 and the tapered annular portion of piece 24. Significantly, an annular space 40 is defined between the outer periphery of dome 36 and the tapered, inner peripheral surface of piece 24, that space conforming in shape to the wall of a suction cup for reasons that will become apparent.

In operation, after a suitable supply of liquid vinyl or other plastisol is inserted into mold body 16, the latter is sealed by the insertion under pressure of mold closure 22 into mold opening 18 in the manner shown best in FIG. 3, such that suction cup forming space 4@ is in direct communication with the interior of the mold. Th plug 22 is then firmly sealed within mold opening 118 such that the tapered outer walls of piece 24 seat against the correspondingly tapered inner wall of ring 20 of the mold body.

The threaded lower end 42 of a pin 44 is received within bore 32. The plug 22, as herein shown, is urged into a secure and intimate sealing engagement with the mold body by means of a spring 46 received within a circular groove 48 formed at the upper end of post 44, after which the sealed mold, filled with the liquid plastic, is rotated, preferably about different axes, to thereby distribute the plastisol over the interior wall of the mold body and in the annular space 40 defined between the two pieces of plug 22. After the liquid plastic material is gelled and fused by the application of heat to the mold, the rotation of the mold is stopped and the mold is cooled. Thereupon, the force exerted by spring 46 upon the plug 22 .is released, by known means not herein shown, to permit the plug to be removed from the mold opening.

Thereafter, the completed article containing an integrally formed suction cup, such as that shown in FlG. l, is removed from the interior of the mold body, after which the mold is readied for the next article-forming operation. The article may then be dyed to be placed in its final form for sale to the consuming public.

The mold and fabricating technique thus far described is highly suitable for use when it is desired to form the integral suction cup at the base of the doll as I shown in FIG. 1. However, the invention may also be employed to fabricate a doll a as shown in FIG. 4, in

which a suction cup 12a is formed integrally at another position on the doll such as at the back of the doll's head as shown in FIG. 4.

Th mold body that is adapted for use in fabricating the doll of FIG. 4 is shown in FIGS. 5 and 6 and includes a mold 14a shaped in conformance to the shape of the doll. Mold 14a has an opening formed at one of its axial ends for receiving therein a conventional mold closure or plug 50 such as that described in US. Pat. No. 2,926,388, in contrast to the mold opening 18 of the embodiment of FIGS. 2 and 3, which, as described above, receives the novel suction cup-forming plug of the invention.

The mold 14a of FIG. 5, in contrast to mold 14 of FIGS. 2 and 3, has a second opening 52 formed therein at a location corresponding to the desired placement of the suction cup on the doll, such as, on the back of the dolls head as shown. Opening 52 is formed similar to the mold opening of the previously described embodiment in that a tapered annular flange 54 surrounds opening 52 which, as shown in FIG. 6, receives a suction-cup forming plug 22a of the invention similar to that described with respect to the earlier described embodiment. That is, plug 22a includes a tapered ringshaped piece 24a and an insert piece 280. The two pieces when joined together by fastening screws 56 define an annular cavity or space 40a corresponding to the configuration of the wall of a suction cup. Mold closure or plug 22a, in contrast to the closure of FIGS. 2 and 3, remains positioned in opening 52 for repeated doll-forming operations and causes each of the fabricated dolls to have a suction cup integrally formed thereon at the location of opening 52 and plug 22a. New plastisol is introduced into the mold interior, for each doll fabrication operation, and the completed doll having the integrally formed suction cup is then removed from the mold by the controlled removal of plug Stl from the bottom mold opening in a conventional manner. 1

Thus, the article fomiing process and apparatus of the invention permits the fabrication of an article, such as a doll, to which a suction cup is integrally formed, by the use of a relatively inexpensive and novel mold closure or plug. A doll or toy having a suction cup inte grally formed thereon at any desired location can thus be manufactured by the apparatus and method of the invention at little or no additional cost.

While the method and apparatus of the invention has been herein specifically disclosed with respect to a rotational casting operatiomit may be employed to comparable advantage with other types of article forming apparatus. Thus, while the invention has been particularly described herein with respect to one embodiment,

it will be apparent that modifications may be made therein all without departing from the spirit and scope of the invention.

We claim:

ll. In combination with a mold having a hollow shaped interior for receiving a supply of liquid molding material, and a mold opening communicating with said interior, a mold closure received in said mold opening and comprising a first annular section having a central opening formed thereinand defined by an interior wall surface tapered downwardly in the direction of the interior of the mold, a second section having a substantially hemispherical lower surface received at least partially within said central opening and spaced from said first and second plurality of openings for securing said first section to said second section, whereby an annular space external to and communicating with said mold interior and substantially conforming to the shape of a suction cup is defined between said first and second sections of said mold closure.

2. The combination of claim 1, :in which said second section further comprises a post extending axially from said opposing surface, said urging means comprising resilient means for engaging said post. 

1. In combination with a mold having a hollow shaped interior for receiving a supply of liquid molding material, and a mold opening communicating with said interior, a mold closure received in said mold opening and comprising a first annular section having a central opening formed therein and defined by an interior wall surface tapered downwardly in the direction of the interior of the mold, a second section having a substantially hemispherical lower surface received at least partially within said central opening and spaced from said interior wall surface, the space between said interior wall surface and said hemispherical surface being at a minimum at the upper end of said interior wall surface and increasing toward the lower end thereof, said first section including a first plurality of openings formed therein, said second section further including a circular flange extending beyond said hemispherical surface and having a second plurality of openings formed therein in substantial registration with said first plurality of openings, and further comprising fastening means passing through respectively registering ones of said first and second plurality of openings for securing said first section to said second section, whereby an annular space external to and communicating with said mold interior and substantially conforming to the shape of a suction cup is defined between said first and second sections of said mold closure.
 2. The combination of claim 1, in which said second section further comprises a post extending axially from said opposing surface, said urging means comprising resilient means for engaging said post. 